diff --git a/src/accountant.rs b/src/accountant.rs
new file mode 100644
index 0000000000..d3a1054c1f
--- /dev/null
+++ b/src/accountant.rs
@@ -0,0 +1,129 @@
+//! The `accountant` is a client of the `historian`. It uses the historian's
+//! event log to record transactions. Its users can deposit funds and
+//! transfer funds to other users.
+
+use log::{verify_entry, Event, PublicKey, Sha256Hash};
+use historian::Historian;
+use ring::signature::Ed25519KeyPair;
+use std::sync::mpsc::{RecvError, SendError};
+use std::collections::HashMap;
+
+pub struct Accountant {
+    pub historian: Historian<u64>,
+    pub balances: HashMap<PublicKey, u64>,
+    pub end_hash: Sha256Hash,
+}
+
+impl Accountant {
+    pub fn new(start_hash: &Sha256Hash, ms_per_tick: Option<u64>) -> Self {
+        let hist = Historian::<u64>::new(start_hash, ms_per_tick);
+        Accountant {
+            historian: hist,
+            balances: HashMap::new(),
+            end_hash: *start_hash,
+        }
+    }
+
+    pub fn process_event(self: &mut Self, event: Event<u64>) {
+        match event {
+            Event::Claim { key, data, .. } => {
+                if self.balances.contains_key(&key) {
+                    if let Some(x) = self.balances.get_mut(&key) {
+                        *x += data;
+                    }
+                } else {
+                    self.balances.insert(key, data);
+                }
+            }
+            Event::Transaction { from, to, data, .. } => {
+                if let Some(x) = self.balances.get_mut(&from) {
+                    *x -= data;
+                }
+                if self.balances.contains_key(&to) {
+                    if let Some(x) = self.balances.get_mut(&to) {
+                        *x += data;
+                    }
+                } else {
+                    self.balances.insert(to, data);
+                }
+            }
+            _ => (),
+        }
+    }
+
+    pub fn sync(self: &mut Self) {
+        while let Ok(entry) = self.historian.receiver.try_recv() {
+            assert!(verify_entry(&entry, &self.end_hash));
+            self.end_hash = entry.end_hash;
+
+            self.process_event(entry.event);
+        }
+    }
+
+    pub fn deposit(
+        self: &Self,
+        n: u64,
+        keypair: &Ed25519KeyPair,
+    ) -> Result<(), SendError<Event<u64>>> {
+        use log::sign_hash;
+        let event = sign_hash(n, &keypair);
+        self.historian.sender.send(event)
+    }
+
+    pub fn transfer(
+        self: &mut Self,
+        n: u64,
+        keypair: &Ed25519KeyPair,
+        pubkey: PublicKey,
+    ) -> Result<(), SendError<Event<u64>>> {
+        use log::transfer_hash;
+        use generic_array::GenericArray;
+
+        let sender_pubkey = GenericArray::clone_from_slice(keypair.public_key_bytes());
+        if self.get_balance(&sender_pubkey).unwrap() >= n {
+            let event = transfer_hash(n, keypair, pubkey);
+            return self.historian.sender.send(event);
+        }
+        Ok(())
+    }
+
+    pub fn get_balance(self: &mut Self, pubkey: &PublicKey) -> Result<u64, RecvError> {
+        self.sync();
+        Ok(*self.balances.get(pubkey).unwrap_or(&0))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::thread::sleep;
+    use std::time::Duration;
+    use log::generate_keypair;
+    use historian::ExitReason;
+    use generic_array::GenericArray;
+
+    #[test]
+    fn test_accountant() {
+        let zero = Sha256Hash::default();
+
+        let mut acc = Accountant::new(&zero, Some(2));
+
+        let alice_keypair = generate_keypair();
+        let bob_keypair = generate_keypair();
+        acc.deposit(10_000, &alice_keypair).unwrap();
+        acc.deposit(1_000, &bob_keypair).unwrap();
+
+        let bob_pubkey = GenericArray::clone_from_slice(bob_keypair.public_key_bytes());
+        acc.transfer(500, &alice_keypair, bob_pubkey).unwrap();
+
+        sleep(Duration::new(0, 1_000_000));
+
+        assert_eq!(acc.get_balance(&bob_pubkey).unwrap(), 1_500);
+
+        drop(acc.historian.sender);
+        assert_eq!(
+            acc.historian.thread_hdl.join().unwrap().1,
+            ExitReason::RecvDisconnected
+        );
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 82be8c1d28..5aef0ab234 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,7 @@
 #![cfg_attr(feature = "unstable", feature(test))]
 pub mod log;
 pub mod historian;
+pub mod accountant;
 extern crate bincode;
 extern crate generic_array;
 extern crate rayon;